Dental mandrel.



TH'E NORRIS PETERS 60., PHOTO-LITHQ. WASHINGTON O. O. SAMPHERE. DENTALMANDRBL. APPLICATION FILED NOV. 22, 1913 Patented Aug. 11, 1914 eras@FFIEE.

DENTAL MANIDREL.

To all whom it may concern:

Be it known that I, ORIN C. SAMPHERE, a citizen of the United States,residing at the city of Milwaukee, county of Milwaukee, and State ofWisconsin, have invented new and useful Improvements in Dental Mandrels,of which the following is a specification. a

My invention relates to improvements in dental mandrels.

The object of my invention is to provide a form of mandrel in connectionwith which a series of operating tools may be interchangeably used andin which each of such tools may be quickly removed and replaced byanother and the replaced tool securely held by,

the mandrel while in use.

In the drawings-Figure 1 is a view of a dental mandrel embodying myinvention, partially broken away to show the gripping tongs and threadedtool shank. Fig. 2 is a detail sectional view, on an enlarged scale, ofthe gripping jaws or chuck and the tool, its shank and the slidinglocking sleeve. Fig. 3 is a similar view, taken at right angles to theview shown in Fig. 2, showing the locking sleeve in releasing position.Fig. 4 is a detail view of a tool and its shank as it appears whendetached, the tool being shown in section. Fig. 5 is a sectional view ofa modified form of tool adapted to be substituted for the one shown inFig. 3.

Like parts are identified by the same reference characters throughoutthe several views.

The body A of the mandrel may be of any ordinary construction. The tooldriving stem or shaft B, however, is provided near its upper end with ahead 0, having a slot D therein and also havinga tubular aperture toreceive the shank E of the tool. The head C is provided with a neck 6,through which the shank E passes and at the outer end of the neck acircular flange e is provided against which the tool F may be clamped.

The inner end of the shank E is screw threaded, and a pair of clutchdogs G are provided with segmental threads on their inner faces adaptedto engage the threads of the shank E. These clutch dogs are supported byarms H, both of said arms being preferably formed of a continuous pieceof metal which is looped across the base of the slot D underneath thecross pin J. The arms H are resilient and tend to hold the Specificationof Letters Patent.

Application filed November 22, 1913. Serial No. 802,447.

Patented Aug. ii, isia.

clutch dogs G out of engagement with the threaded shank E. They may bepressed into such engagement, however, by a sleeve K, which maybeadjusted longitudinally to bear upon the projecting outer portions ofthe dogs and force them inwardly. The outer end of the shank E isprovided with a head L and a suitable washer L, preferably non-metallic.

. When the dogs are in engagement with the threads of the shank E, arotation of the stem or shaft B may be transmitted to the shank E andthe tool. But if the tool and shank E be held against rotation, then therotation of the stem B and head C in one direction will cause the shankE to screw feed inwardlyuntil the tool is securely clamped against theflange e, whereupon it will no longer be possible to hold the toolagainst rotation, if stem B and head G continue to rotate in thatdirection. If the direction of rotation is reversed and the tool andshank E held, shank E will unscrew and the tool will become loose, butthe tool will ordinarily be driven (rotated) in the direction whichtends to clamp it to the flange e.

By moving sleeve K to the releasing position shown in Fig. 3, shank Ewill be released, for the arms H will then retract the dogs G. The tooland shank E may then be freely withdrawn. When withdrawn, the tool F(which may be assumed to consist of a sand paper disk), may be slippedfrom the shank, and a grinding wheel M similar to that shown in Fig. 5or any other suitable form of tool, may be substituted. The arms H,being engaged underneath the cross pin J, are in loose connection withthe head 0 and this allows the pressure of the dogs to equalize. Iprefer, however, to depend upon the resilience of the arms to retractthe dogs G from clutching position, since the retracting movement isthus made positive and automatic. The sleeve K may, if desired, be madelong enough to cover the joint be tween the projecting head O and thetapered extremity O of the body A, thus tending to exclude saliva fromthis oint when the tool isin operation in the mouth of a patient. Theneck 6 enables me to locate the adjustable sleeve and the clutch dogs ata sufiicient distance from the tool to facilitate manipulation of thesleeve.

I claim 1. A dental mandrel including a driving shaft provided with ahead, a pair of clutch dogs adjustably connected With the head andhaving their inner faces threaded, a tool engaging shank fitted to thehead and provided with a screw thread adapted to be engaged by thethreaded portions of said clutch dogs, and a clutch setting sleeveslidably mounted upon said head and adapted in one position to hold thedogs in screw connection with said shank.

2. A dental mandrel including a driving shaft provided With a head and aneck portion having a tool receiving extremity, a

pair of clutch dogs adjustably' connected said extremity of the neckportion.

3. A dentalmandrel, comprising the combination of a relativelystationary body, a driving shaft extending therethrough and providedwith a slotted head, said head having a longitudinal shank receivingaperture,

a screw threaded tool holding shank adapt, ed to enter the aperture insaid head, a set of clutch dogs and press them inwardly when the sleeveis in one position of adjustment, whereby said dogs are brought intoengagement with the threaded tool holding shank.

In testimony whereof I atfix my signature in the presence of tWowitnesses. v

,ORIN O SAMPHERE. Witnesses: Y a

' JAS. B. ERWIN,

IRMA D. BREMER.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents.

. Washington, L03 i V

